Plants Furnish Society with More Than Food

- Plants provided early societies with shelter, clothing and fuel
- humans have used biomass energy from plants (as fuels) for millenia
- Modern civilizations: plants provide various media for written communications
- Future civilizations: Are plant based products to answer to some of societies biggest problems
The Most Vintage Crafts: Basket Weaving
- Basketry present in every human culture
- tough to date, because perishable
- Egyption baskest = 10,000 years old
- predates pottery!!!
- Early humans may have used bird’s nests
- Basket making does cross gender barriers
- Plants used for baskets region dependent
- palm and coconut in tropics
- tree parts in temperate regions
- grasses in prairies

Plant Fibers
- Fiber: long tapering plant cells with cellulose
- ground tissues: sclerenchyma cells
- thick cells walls
- lignin, tannin, pectin
- Most valuable fibers are mostly cellulose and white
- cellulose has tensile strength of steel
- Commercial fibers are elongate masses of plant material
- not individual cells
- limited # of plant species
- Provide cloth, rope, paper, etc for millennia
- rope from flax 30,000 years ago

RSW1 Gene Breakthrough
- RSW1 gene codes for the enzyme responsible for cellulose production
- Isolated in Arabidopsis and cotton
- Can scientists manipulate cellulose content of plants used for fibers?

Fiber Types
- Natural fibers are plant or animals based
- synthetics may still use natural sources
- rayon still has cellulose from wood pulp
- Classified according to use:
- textile fibers: used to weave cloth
- cordage fibers: used to make rope
- filling fibers: used to stuff things
- Classified from source on plant:
- surface fibers: coverings of leaf, fruit, seeds
- soft fibers: clusters of phloem fibers
- hard/leaf fibers: veins of leaves

Extracting fibers and Spinning Yarn
- Surface fibers separated from plants mechanically


Extracting Fibers and Spinning Yarn
- Surface fibers separated from plants mechanically
- Soft fibers extracted using microbial degradation
- retting, removes soft tissues
- Hard fibers scraped away by hand or machine
- First spinning wheel in India ~750 a.d
- big advancements during industrial revolution

King Cotton
- Rendering cotton into cloth was discovered independently in new & old worlds
- Harvested from wild plant in coastal Peru 10,000 years ago
- domesticated 4,500 years ago
- Cotton cloths dates 5,000 years in India
- spread to Babylonia
- Arabs brought cotton to Spain
- Cotton brought to Florida in 1556
- commercial crop from southern colonies

Cotton Plant
- 20-30 species in the genus (Gossypium)
- native to Asia, Africa, Americas and Australia
- shrub with palmate leaves
- warm climate with lots of water
- Currently the most popular natural fiber
- Fruit of cotton is a capsule, splits along 5 seams
- fibers are hairs that extend from seed coats (10)
- 20,000 hairs per seed
- hairs naturally twisted

Bioengineered Cotton
- Bollgard = Bt cotton created by Monsanto
- effective against many cotton pests
- bollworms and budworms
- one of most planted transgenic crops
- Bt cotton yield gain +10% in USA
- large reductions in insecticide use
- Bollworm pests damage higher in India
- small farms cannot afford insecticides
- yields increase 60% with Bt
- Transgenic research combines cotton & polyester
- feel of cotton + heat retention
- ‘natural’ cotton-poly blend


Linen: An Ancient Fabric

- Flax (genus Linus) delicate, long, slender stems
- May be oldest plant fiber used to make cloth
- 30,000 year old wild flax fibers in cave used during stone age
- used to bind tools or weave baskets?
- fibers appear to have been dyed!
- Ancient Egypt was the ‘land of linen’
- worn by royalty or in mummy cloths
- exported for use in sails
- Grown in Soviet Union, China and Western Europe
Plant Fibers Vary by Region and Culture

Wood and Wood Products
- Ranks next to food in importance to human society
- construction, fuel, synthetics
- strength & insulating properties (construction)
- 1/3 of land surfaces covered by forests
- 7.5 million hectares removed a year
- long history: humans w/ fire
- Usage rate exceeds regeneration
- Forest removal greater for agriculture than for timber

Billion to Trillion Tree Campaigns

Hardwoods vs Softwoods
- Wood is secondary xylem (vascular cambium)
- lots of strong (cellulose) dead cells
- Wood strength determined by cell wall thickness, types of xylem cells & fibers
- Hardwood lumber = angiosperm trees
- Softwood lumber = gymnosperm trees (conifers)
- Generally angiosperm lumber is more dense

Wood for Fuel
- Chief source of fuel until recent times
- Developing nations still depend on wood for fuel
- 2 billion people use for heating/cooking
- prominent in the tropics
- Charcoal production originated 7,000 years ago
- partial combustion with low air flow
- burns at higher temperatures
- caused the decimation of European forests

Pulp and Paper
- Wood pulp = watery suspension of pulverized wood
- mostly xylem cells and fibers
- ~50% of harvested wood goes to pulp
- processing removes lignin (brown color)
- Traditional processing (chlorine) harmful to environment
- utilization of wood-rotting fungi
- transgenic Eucalyptus w/ low lignin
- Wood pulp used for paper, cardboard and cellophane
- Each American uses 700 lbs of paper
- despite the internet
- 1 billion trees harvested a year

The Future of Paper: Hemp? Again?

